This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. After our initial successes with 2D-ELDOR at 95 GHz, we have developed the hardware necessary for performing step-frequency versions of the ELDOR experiment, to study dynamics, as well as DEER, with the goal of studying distances in spin-labeled proteins. We are now working on the appropriate control software to integrate the step-frequency capability into our existing pulse spectrometer at 95 GHz. This software will also have a hook to enable us to integrate step-field capability into the suite of experiments we can perform at 95 GHz. These flexible scripts, based on the public domain python scripting language, will be made available on request for further development by collaborators and colleagues to whom we fulfill service requests. We expect that knowledge and use of these scripts will aid in the design of future experiments that will help us unravel the details of structure and dynamics in complex biological systems.